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• 1. [Article] Measuring the Value of Forage Fish to Recreational Fishermen

  Fisheries management has been traditionally single-species oriented. Only recently more pressure has been put on developing a holistic, science-based approach that considers the ecosystem as a whole. This ...

  Citation × Citation Citation Abstract Copy Title: Measuring the Value of Forage Fish to Recreational Fishermen Author: Lipton, Doug, Hutniczak, Barbara, Townsend, Howard Fisheries management has been traditionally single-species oriented. Only recently more pressure has been put on developing a holistic, science-based approach that considers the ecosystem as a whole. This approach is widely known as ecosystem-based fisheries management (EBFM). One of the most often highlighted aspects of EBFM is the relevance of predator-prey interactions in the aquatic ecosystems. The motivation is that there are considerable trade-offs between the supporting role of forage species as energy conveyors in food webs and provisioning service as target species to fisheries. We study this aspect by looking at the Chesapeake Bay. The motivation is a recent debate on the potential impact of excessive forage base fishing. In particular, we are interested in the propagation of forage overfishing through the food web and its influence on more valuable, higher trophic species fisheries. We develop a Bayesian model of recreational harvest of striped bass where benefits are derived from stock size as well as age structure. The age structure drives the probability of catching a fish of a particular size what is of considerable importance to the fishery highly constrained by minimum catch size regulations. Then, using a dynamic multispecies framework (Ecosim) and modified random utility model, we analyze multiple scenarios varying by menhaden regulations and derive benefits changes imposed on the striped bass recreational fishery. We focus on the recreational sector as recent research indicates that the recreational fishing is becoming increasingly important and new management strategies may be necessary to address this shifting trend. Title: Measuring the Value of Forage Fish to Recreational Fishermen Author: Lipton, Doug, Hutniczak, Barbara, Townsend, Howard Fisheries management has been traditionally single-species oriented. Only recently more pressure has been put on developing a holistic, science-based approach that considers the ecosystem as a whole. This approach is widely known as ecosystem-based fisheries management (EBFM). One of the most often highlighted aspects of EBFM is the relevance of predator-prey interactions in the aquatic ecosystems. The motivation is that there are considerable trade-offs between the supporting role of forage species as energy conveyors in food webs and provisioning service as target species to fisheries. We study this aspect by looking at the Chesapeake Bay. The motivation is a recent debate on the potential impact of excessive forage base fishing. In particular, we are interested in the propagation of forage overfishing through the food web and its influence on more valuable, higher trophic species fisheries. We develop a Bayesian model of recreational harvest of striped bass where benefits are derived from stock size as well as age structure. The age structure drives the probability of catching a fish of a particular size what is of considerable importance to the fishery highly constrained by minimum catch size regulations. Then, using a dynamic multispecies framework (Ecosim) and modified random utility model, we analyze multiple scenarios varying by menhaden regulations and derive benefits changes imposed on the striped bass recreational fishery. We focus on the recreational sector as recent research indicates that the recreational fishing is becoming increasingly important and new management strategies may be necessary to address this shifting trend. Close

• 2. [Article] Fishermen's Location Choice under Spatio-Temporal Update of Expectations

  Information acquired by fishermen while fishing play a crucial role in their decision-making process. Those are used to form the basis for update of beliefs on productivity of a range of available fishing ...

  Citation × Citation Citation Abstract Copy Title: Fishermen's Location Choice under Spatio-Temporal Update of Expectations Author: Munch, Angela, Hutniczak, Barbara Information acquired by fishermen while fishing play a crucial role in their decision-making process. Those are used to form the basis for update of beliefs on productivity of a range of available fishing grounds while acting in an uncertain environment. In this paper, we focus on the formation of fishermen's beliefs about the productivity of fishing grounds based on signals obtained through harvest activity. We task ourselves with better understanding of the impact of prior experience on the at-sea day-to-day decision with respect to location choice. We investigate how obtained signals are propagated over time and space considering knowledge decay with increasing spatial and temporal separation, hence, incorporating intertemporal and spatial correlation between gained experience and future expectations. The parameters of the updating process are derived by fitting a dynamic Bayesian model to available data of location choices. The signal propagation parameters are derived by fitting the multinomial logit model to simulated expectations data paired with observed discrete location choices. Our motivation is that successful fisheries management must be able to accurately predict the response of fishermen to fishery regulations with particular attention paid to flexible technologies where individuals can adjust effort and alter fishing behavior. Good understanding of fishermen location choice and location adjustment flexibility can contribute substantially to a design of management practices with spatial components. We apply our model to the Polish bottom trawler fleet in the Baltic Sea. Title: Fishermen's Location Choice under Spatio-Temporal Update of Expectations Author: Munch, Angela, Hutniczak, Barbara Information acquired by fishermen while fishing play a crucial role in their decision-making process. Those are used to form the basis for update of beliefs on productivity of a range of available fishing grounds while acting in an uncertain environment. In this paper, we focus on the formation of fishermen's beliefs about the productivity of fishing grounds based on signals obtained through harvest activity. We task ourselves with better understanding of the impact of prior experience on the at-sea day-to-day decision with respect to location choice. We investigate how obtained signals are propagated over time and space considering knowledge decay with increasing spatial and temporal separation, hence, incorporating intertemporal and spatial correlation between gained experience and future expectations. The parameters of the updating process are derived by fitting a dynamic Bayesian model to available data of location choices. The signal propagation parameters are derived by fitting the multinomial logit model to simulated expectations data paired with observed discrete location choices. Our motivation is that successful fisheries management must be able to accurately predict the response of fishermen to fishery regulations with particular attention paid to flexible technologies where individuals can adjust effort and alter fishing behavior. Good understanding of fishermen location choice and location adjustment flexibility can contribute substantially to a design of management practices with spatial components. We apply our model to the Polish bottom trawler fleet in the Baltic Sea. Close